fix(useFilenamingConvention): allow leading digits in lower-like cases

[Conaclos]

Summary

Fix #3952
Leading ASCII digits inside a name are now considered as lowercase characters.
2024-09-17-filename, 2024_09_17_filename, 20240917FileName and 20240917filename are recognized as kebab-case, snake_case, camelCase and lowercase respectively.
2024FILENAME and 2024_FILE_NAME are not recognized as UPPERCASE and CONSTANT_CASE.

Test Plan

I updated the changed snapshot.

[codspeed-hq]

CodSpeed Performance Report

Merging #3957 will degrade performances by 7.52%

_{Comparing conaclos/useFilenamingConvention-allow-number-in-lowercase-like (568cd95) with main (e1851e2)}

Summary

⚡ 2 improvements
❌ 1 regressions
✅ 104 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	main	conaclos/useFilenamingConvention-allow-number-in-lowercase-like	Change
⚡	pure_9395922602181450299.css[cached]	3.6 ms	3.4 ms	+6.41%
⚡	router_17129688031671448157.ts[cached]	2.2 ms	2.1 ms	+6.95%
❌	db_17847247775464589309.json[uncached]	15.1 ms	16.3 ms	-7.52%